Typical crawler tracks for track-type vehicles such as bulldozers and hydraulic shovels are structured such that iron shoe plates having grousers on their ground engaging side are endlessly coupled by a number of links. Crawler tracks of this type cause serious damage to the road surface when traveling on a paved road and therefore, the ground engaging side of each iron shoe plate is provided with a protective track shoe (elastic track shoe) made from an elastic material such as rubber.
One example of conventional elastic shoes has been disclosed in Japanese Utility Model No. 2595443 according to which a metal plate is corrugated so as to conform to the irregular shape of the tread of an iron shoe plate and a rubber pad is bonded by vulcanization to the ground engaging side of the metal plate. Another example has been disclosed in Japanese Utility Model No. 2606785. The elastic track shoe of this utility model is designed such that a planar metal plate is attached only to the convex surface of an irregular-shaped elastic shoe member with mounting bolts whose leading ends project toward a side opposite to the ground engaging side (this side is hereinafter referred to as “non ground engaging side”). Japanese Kokai Patent Publication No. 10-16835 discloses another track shoe in which substantially U-shaped mounting brackets are integrally formed with the non ground engaging side of a planar plate so as to be inserted in the recesses of the shoe plate and the mounting brackets have bolt holes corresponding to the mounting holes of the shoe plate.
The track shoes disclosed in Japanese Utility Model Nos. 2595443 and 2606785 have the problem that since they are designed to have fastening members such as bolts welded to the core bar made from sheet metal, sufficient rigidity cannot be ensured, so that loosening and coming-off of the bolts are likely to occur resulting from occurrence of deflection and distortion. On the other hand, the track shoe disclosed in Japanese Patent Kokai Publication No. 10-16835, which is joined to the shoe plate through the mounting brackets, can attain improved mounting strength, but has revealed such a disadvantage that the thickness of the elastic body subjected to a load cannot be increased. This leads to strain concentration upon the elastic body, resulting in poor durability.
The present invention is directed to overcoming the foregoing problems and a primary object of the invention is therefore to provide an elastic track shoe in which loosening of the bolts is prevented by use of a rigid core bar and the thickness of the elastic body subjected to a load is increased irrespective of the grousers to improve the durability of the track shoe.